Mistrials and Motions for a Finding of Not Guilty
Key takeaways
- A mistrial is a drastic remedy: proper only when manifestly necessary in the interest of justice, because circumstances cast substantial doubt on the trial’s fairness or impartiality. United States v. Waldron, 36 C.M.R. 126 (C.M.A. 1966).
- Judges must consider alternatives first — curative instructions defeat most mistrial motions, but not all: some prejudice no instruction can cure. United States v. Diaz, 59 M.J. 79 (C.A.A.F. 2003).
- After a mistrial the government can usually re-refer the charges — unless the defense objected and the judge abused discretion, or intentional prosecutorial misconduct induced the mistrial. R.C.M. 915(c)(2).
- R.C.M. 917 sets a deliberately low bar for the government: the motion is denied if any evidence, with reasonable inferences, could reasonably tend to establish every element.
- The asymmetry is absolute: a denied 917 motion can be reconsidered until the record is authenticated; a granted one can never be reconsidered.
Two different emergency valves
Most court-martial motions are litigated before the members are ever seated. These two are different: they are made during trial, when something has already gone wrong. A mistrial motion says the proceedings themselves have been contaminated and must end. An R.C.M. 917 motion says the government’s proof has failed as a matter of law and the judge should acquit without waiting for the members. They share a courtroom but almost nothing else:
| Mistrial — R.C.M. 915 | Finding of not guilty — R.C.M. 917 | |
|---|---|---|
| Claim | The trial’s fairness is in substantial doubt | No evidence supports an essential element |
| Who raises it | Either party, or the judge sua sponte | Defense motion, or the judge sua sponte |
| When | Any point where prejudice emerges | After the evidence on either side closes, before findings are announced |
| Effect if granted | Affected charges withdrawn from the court-martial; government can usually re-refer | Acquittal on the charge or the affected part — final and unreviewable |
| Reconsideration | Ruling reviewable like other rulings | Denial: reconsiderable until authentication. Grant: never |
The mistrial standard: manifest necessity
The controlling formulation is a half-century old and still governs:
The judge should declare a mistrial only when “manifestly necessary in the interest of justice” due to circumstances which “cast substantial doubt upon the fairness or impartiality of the trial.”United States v. Waldron, 36 C.M.R. 126, 129 (C.M.A. 1966)
The standard cuts both ways. It makes mistrials hard for the defense to win — but it also polices judges who reach for the remedy too quickly, since a mistrial granted without manifest necessity can bar retrial altogether. In United States v. Brooks, 42 M.J. 484 (C.A.A.F. 1995), CAAF held a military judge should not have declared a mistrial based on his own improper inquiry into the members’ deliberative process. When granted, a mistrial withdraws the affected charges and specifications from the court-martial; it may reach some charges and not others, findings or sentencing alone.
Alternatives first: the curative-instruction gauntlet
Because the remedy is drastic, judges must consider lesser measures before granting one — and the case law is a catalog of curative instructions doing the work. An immediate instruction (repeated during findings) cured a witness’s reference to the accused’s discharge request in United States v. Balagna, 33 M.J. 54 (C.M.A. 1991). Instructions cured trial counsel’s improper gang-affiliation references in opening — even though members kept asking about the topic. United States v. Taylor, 53 M.J. 195 (C.A.A.F. 2000). Individual assurances from each member that they would disregard testimony about a dismissed specification sufficed in United States v. Skerrett, 40 M.J. 331 (C.M.A. 1994).
But the gauntlet is not unrunnable. In United States v. Diaz, 59 M.J. 79 (C.A.A.F. 2003), two witnesses — one an expert — testified that the death of the accused’s daughter was a homicide and that the accused was the perpetrator. CAAF held denial of the mistrial an abuse of discretion: the combined prejudice went to the two central issues in the case, cause of death and identity, and no instruction could dislodge it. The defense playbook follows directly: tie the tainted material to the core contested issues, and show why an instruction asks members to do the impossible.
What has — and hasn’t — justified a mistrial
The reported grounds cluster into three families:
- Member misconduct and exposure. A member’s extensive, self-initiated communications with a third party to gather extrajudicial information about key issues warranted mistrial. United States v. Knight, 41 M.J. 867 (A. Ct. Crim. App. 1995). By contrast, a member inadvertently glimpsing autopsy photos, a government witness sharing a ride with a member (United States v. Johnson, 23 M.J. 327 (C.M.A. 1987)), an inattentive member (United States v. West, 27 M.J. 223 (C.M.A. 1988)), and trial counsel’s improper but information-free small talk with the panel president — cured by removing the president for cause (United States v. Hamilton, 41 M.J. 22 (C.M.A. 1994)) — did not require one.
- Judicial overreach. A mistrial should have been granted where the judge asked the members to hold the defense counsel in contempt — and they did — because even the threat, made before the members, poses a substantial risk of prejudice. United States v. Burnett, 27 M.J. 99 (C.M.A. 1988). And a judge need not declare a mistrial over defense objection when the defense would rather press on. United States v. Donley, 33 M.J. 44 (C.M.A. 1991).
- Discovery violations at trial. Where trial counsel elicited undisclosed statements and testimony that the accused had invoked his rights, curative instructions sufficed — but the episode shows how discovery failures surface mid-trial as mistrial litigation. United States v. Palumbo, 27 M.J. 565 (A.C.M.R. 1988).
After a mistrial: when retrial is barred
The default is that a mistrial does not end the case: the government can usually re-refer the affected charges, even after a mistrial in a judge-alone trial. United States v. Mora, 26 M.J. 122 (C.M.A. 1988). But R.C.M. 915(c)(2) carves out two situations in which former jeopardy bars any retrial, where the mistrial was declared after jeopardy attached and before findings:
- Defense objection plus abuse of discretion. In Burtt v. Schick, 23 M.J. 140 (C.M.A. 1986), trial counsel sought a mistrial after the defense revealed an accomplice’s sentence; the judge granted it over defense objection, that grant was an abuse of discretion, and double jeopardy barred any retrial.
- Intentional prosecutorial misconduct that induces the mistrial. The bar requires intent to goad. Where trial counsel’s cross-examination elicited an undisclosed juvenile arrest record and the defense won its mistrial, the conduct did not rise to intentional misconduct — so retrial was permitted. United States v. Diangelo, 31 M.J. 135 (C.M.A. 1990).
The strategic consequence: a defense team requesting a mistrial should think two moves ahead, because the usual prize is a second trial for the government — with a preview of the defense case included. Sometimes the better play is the curative instruction plus a preserved objection; the calculus belongs with the endgame of findings in view.
What this means if something went wrong at your trial
If a member saw or heard something they should not have — or a witness blurted out the inadmissible — the next hours matter enormously. Whether your counsel moves for mistrial, demands individual voir dire of the members, insists on a curative instruction, or deliberately declines one is a chess decision: a mistrial usually hands the government a rehearsal-informed second trial, while a preserved objection may serve you better on appeal. These calls have to be made in the moment, on the record, by counsel who has made them before. Make sure yours has.
R.C.M. 917: the any-evidence standard
The motion for a finding of not guilty is the military’s directed-verdict motion, and its standard is written for the government: the motion is denied if there is any evidence which, together with all reasonable inferences and presumptions, could reasonably tend to establish every element of the offense. The evidence is viewed in the light most favorable to the prosecution, with no evaluation of witness credibility — so a judge properly denied the motion despite alleged deviations from a drug lab’s standard operating procedures. United States v. Felix, 25 M.J. 509 (A.F.C.M.R. 1987).
The motion wins when the government’s proof is not merely weak but absent. In United States v. Parker, 59 M.J. 195 (C.A.A.F. 2003), the government charged a rape in 1995; the complaining witness testified the rape occurred in 1993, and the government introduced no evidence of any sexual interaction in the charged year. CAAF held the judge erred in denying the 917 motion — a variance instruction could not substitute for evidence of the offense actually charged. Parker is the template: match the government’s evidence against each element as charged, including dates and places, and move on every element the proof skipped.
R.C.M. 917 mechanics: timing, specificity, effect
The mechanics reward precision:
- Who and when. The judge may act sua sponte or on defense motion, after the evidence on either side is closed and before findings are announced.
- Specificity. The defense must state specifically where the evidence is insufficient, and opposing counsel must be given an opportunity to be heard. A shotgun “insufficient on all elements” motion preserves little.
- Partial grants. A motion granted as to part of a specification may leave a lesser included offense standing.
- The one-way ratchet. A denied motion may be reconsidered at any time before the record of trial is authenticated. R.C.M. 917(f). A granted motion may never be reconsidered — it is an acquittal.
The reconsideration window is more powerful than it looks. In United States v. Griffith, 27 M.J. 42 (C.M.A. 1988), a judge who had denied a 917 motion believed he had no power to set aside the members’ guilty findings. The court corrected him: a military judge who becomes aware, before authenticating the record, of an error that has prejudiced the accused — member misconduct, misleading instructions, or insufficient evidence — may take remedial action. For the defense, that means a denied 917 motion is not dead until authentication: renew it after findings, and again if post-trial matters expose the government’s gap.
Practitioner’s note
We treat R.C.M. 917 as a checklist exercise, not a gesture: before the government rests, we have an element chart for every specification, filled in witness by witness, and the motion targets the specific boxes the government left empty — dates and locations included, because Parker teaches that a wrong year is a missing element. On mistrials, our default is the opposite of reflexive: we ask first whether a curative instruction plus a clean objection serves the client better than gifting the government a second, better-prepared trial. When we do move for mistrial, we build the Diaz record — showing exactly why this prejudice, on these central issues, is beyond any instruction’s reach.
Frequently asked questions
What is a mistrial in a court-martial?
A declaration by the military judge that ends the trial — as to some or all charges — because circumstances cast substantial doubt on its fairness or impartiality. It is a drastic remedy, proper only when manifestly necessary in the interest of justice, and its effect is to withdraw the affected charges from that court-martial.
Can the government retry me after a mistrial?
Usually yes — the charges can be re-referred to a new court-martial. Retrial is barred only in two situations: the mistrial was granted over defense objection and the judge abused his discretion, or intentional prosecutorial misconduct was designed to provoke the mistrial. Ordinary government blunders, even serious ones, do not bar a second trial.
Why do curative instructions defeat most mistrial motions?
Because the law presumes members follow instructions, judges must try lesser measures before the drastic one. Courts have upheld instructions curing improper references to discharge requests, gang affiliation, and dismissed specifications. The presumption breaks only where the prejudice strikes the core contested issues so hard that no instruction can realistically undo it, as in United States v. Diaz.
What is a motion for a finding of not guilty under R.C.M. 917?
The military equivalent of a directed-verdict motion: after the evidence on either side closes and before findings, the defense asks the judge to acquit because no evidence, with all reasonable inferences, could establish every element. The evidence is viewed most favorably to the prosecution, without weighing credibility — so it wins only where proof of an element is truly absent.
Can a judge change a ruling on an R.C.M. 917 motion?
Only in one direction. A denied motion may be reconsidered at any time before the record of trial is authenticated — even after the members return guilty findings. A granted motion is an acquittal and may never be reconsidered. That asymmetry is why defense counsel renew denied motions rather than abandon them.
About the attorneys behind this guide
Michael Waddington, Civilian Military Defense Lawyer
Michael Waddington has spent more than 25 years making split-second trial decisions — when to move for mistrial, when to take the curative instruction, when the government’s case has quietly skipped an element. As a former Army prosecutor and defense counsel and a trial advocacy instructor and author on cross-examination, he has tried courts-martial worldwide, including Article 120 and war crimes cases where a single blurted answer or missing date changed the trajectory of the trial.
Alexandra González-Waddington, Founding Partner
Alexandra González-Waddington, founding partner of Gonzalez & Waddington, has defended service members for more than 20 years in trials where panel contamination, mid-trial disclosure failures, and thin government proof demanded immediate, on-the-record responses — from sexual assault and domestic violence cases to murder prosecutions. She builds element charts against every specification she tries, and she legally reviewed this page against R.C.M. 915, R.C.M. 917, and the governing case law.
Talk to a civilian court-martial defense lawyer today
Gonzalez & Waddington defends Soldiers, Sailors, Airmen, Marines, Guardians, and Coast Guardsmen worldwide — in UCMJ investigations, courts-martial, Article 15/NJP actions, GOMOR rebuttals, administrative separation boards, and Boards of Inquiry. We defend the whole case: the investigation, the trial, the administrative fallout, and the long-term consequences to your rank, retirement, clearance, and discharge.
Sources for this guide include the Uniform Code of Military Justice, the Manual for Courts-Martial (2024 ed.), the Rules for Courts-Martial, the TJAGLCS Criminal Law Deskbook, and the cited decisions of the Court of Appeals for the Armed Forces and the service Courts of Criminal Appeals. It is attorney advertising and general legal information — not legal advice, and reading it does not create an attorney–client relationship. Every case turns on its own facts. Service procedures vary; Army references (AR 27-10) are noted where used.